The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, the approaches described in this section may not be prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
The proliferation of computer technology and the growth of the Internet have greatly increased access to electronic information. The concerns over unauthorized access to electronic documents that contain confidential or sensitive information apply when those electronic documents are destined for printing after being submitted to a printer by scanning or transmitted to the printer via a computer network or the Internet.
Other types of concerns over unauthorized access to electronic documents containing confidential or sensitive information applies to electronic documents submitted to a printer by an authorized creator of the document, but printed by an unauthorized party. In this case, when an electronic document containing confidential or sensitive information is insecurely stored in a printer's memory, an unauthorized party, who gains access to the printer, may release the printing job containing the confidential document and potentially produce a number of unauthorized copies of that document.
Other types of concerns over unauthorized access to electronic documents containing confidential or sensitive information applies to electronic documents transmitted in an unencrypted form. If an electronic document is transmitted in an unencrypted form via a communications link to the printing device, an unauthorized party, who gains access to that communications link, can also easily intercept the electronic document in the unencrypted form. For example, an unauthorized party may eavesdrop on a wired communications link to gain access to electronic documents. Wireless networks are particularly vulnerable because an eavesdropper does not need physical access to a wired network and can instead eavesdrop remotely. Thus, an unauthorized party can monitor wireless communications with a printing device and intercept electronic documents being transmitted to the printing device.
Many approaches have been developed to prevent unauthorized access to electronic documents that contain confidential or sensitive information. For example, users of printing machines may have to be authenticated before they may proceed with printing, copying or document scanning jobs.
Numerous protection schemes have been implemented to secure electronic documents transmitted for printing. For example, electronic documents are encrypted before they are transmitted over public networks, such as the Internet. This makes it difficult, if not impossible, depending upon the encryption used, for an unauthorized party who intercepts an encrypted electronic document to recover the original electronic document.
Other solutions offer a so called “locked printing” feature. Printing devices configured with locked printing provide some type of control over the printing of electronic documents. When a printing device is configured with a locked printing and print data is sent to the printing device, a printed version of an electronic document is not generated until a recipient is verified at the printing device. Typically the recipient enters authentication data, such as a password, through an operation panel on the printing device. The printing device verifies the authentication data, and if successful, the printing device allows the electronic document to be printed.
One of the problems with conventional locked printing approaches is that the documents stored on a printing device are susceptible to unauthorized access by third parties. Locked print documents are conventionally stored on a printing device until an authorized recipient prints the locked print documents. During that time, an unauthorized third party may attempt to enter valid authentication data and gain access to the locked print data stored on the printing device. This is particularly problematic in situations where the locked print data contains sensitive information.
Based on the foregoing, there is a need for an approach for securely printing electronic documents that does not suffer from limitations of prior approaches.